Saturday, May 07, 2011 

22 Years of LASIK

The first FDA clinical trial in the United States began in 1989. At that time, LASIK was not available, so the early procedures were PRK, or photorefractive keratectomy. PRK treats the surface of the cornea with the excimer laser. In contrast, LASIK creates a thin flap in the cornea, laser treatment is applied to the corneal bed, and the flap is repositioned. We still perform PRK in about 10% of our patients, and seeing these patients after fifteen or twenty years reminds me what a great procedure PRK is. LASIK is probably even a better procedure than PRK, and this is why 90% of our patients chose LASIK. The use of the femtosecond laser (IntraLase) has improved the safety and accuracy of LASIK by leaps and bounds.

The visual results in LASIK and PRK are the same. The big difference is in the recovery time. LASIK patients obtain good vision a day or two after their procedure, whereas PRK patients may take a week, or two, to recover. There is also more postoperative pain with PRK, although we have some pretty good ways of minimizing the pain. So, why do some patients still have PRK rather than LASIK? There are four reasons. 1. The cornea may be too thin for LASIK, but thick enough for PRK. 2. There may be some corneal irregularities, or scars, which make PRK a safer procedure than LASIK. 3. There may be concern about displacement of the LASIK flap in people subject to head, or eye, trauma. 4. If previous corneal surgery was done, PRK may be a better option.

Both LASIK and PRK are remarkable for the stability of the vision correction. Less than 10% of patients require a touch-up, or “enhancement” procedure. In our practice, 92% have not needed an enhancement. And when enhancements are done, the cost is minimal, the improvement is predictable, and recovery is quick. Looking back over the last two decades, a few facts are striking. Patients often say that laser vision correction was the best thing they ever did. The elimination of glasses or contact lenses overnight is a truly remarkable feature for any ophthalmic procedure, or any surgical procedure at all. The safety of LASIK and PRK with modern technology is impressive. Serious adverse events are far less than one percent.

Laser vision correction is probably the best procedure to come along in ophthalmology during the last fifty years. What are the challenges for the future? Well, it would be nice to create a bifocal effect in the cornea, so people over 43 years of age would not have to wear reading glasses. But, this seems like such a difficult optical feat, it may be many years before someone figures out how to do it. In the mean time, patients over 43 can chose monovision, or buy reading glasses in the drug store.


Hyperopia Double Whammy

Earlier this week, I performed LASIK on a friend in his late forties. This man had a +2.00 distance correction. That is, he was moderately farsighted, or hyperopic, in both eyes. Before surgery, he was having trouble biking, seeing road signs, and reading small print. When he returned the day after surgery he was 20/20 in both eyes, and reading the newspaper without his glasses. He was thrilled! He had not been able to see clearly for either distance or near for many years. I call this the “double whammy” of performing LASIK for farsightedness in people over 42. Their distance vision becomes excellent. Their reading vision also improves. Sometimes they end up in a “sweet spot” with good distance vision and good reading vision. I tell farsighted patients that their distance vision will be superb, and their reading vision will improve about 30%. I tell them they will, at some point, need reading glasses for fine print. They will probably need to make a trip to the drugstore to get over-the-counter magnifying glasses. My friend was probably a little disappointed when I told him his good reading vision may not last permanently. With age, and possible regression of the laser correction, he might need reading glasses in the next few years. I am sure he will enjoy good reading vision while it lasts, but he won’t be too surprised if he needs the help of magnifying glasses down the road. With nearsighted people, distance vision is also superb after LASIK. But, in people over 42, reading vision may be worse. In nearsightedness, or myopia, there is a “yin and yang” between distance and near. Most people prefer good distance vision over good reading vision. But, it is important that they be forewarned. We spend a good deal of “chair time” discussing presbyopia, the need for reading glasses, with our LASIK patients.

It is sometimes said that farsighted people are easier to please with LASIK. It is this double whammy of improved distance and reading vision that is responsible for their satisfaction.

About me

  • I'm LASIKblog
  • From La Jolla, California, United States
  • Mitchell Friedlaender, M.D., is Head of the Division of Ophthalmology, and Director of the Laser Vision Center at Scripps Clinic, in La Jolla, CA, and Adjunct Professor at The Scripps Research Institute. He is a cum laude graduate of the University of Michigan Medical School, and received his ophthalmology training at Harvard University, and the University of California, San Francisco. He was a full time faculty member at the University of California, San Francisco before joining Scripps Clinic in 1986. He is the author of 6 books and over 250 scientific articles. He has lectured at universities throughout the world on conditions such as blepharitis, allergy, dry eye, and infection. He is the recipient of the Senior Honor Award of the American Academy of Ophthalmology, and a member of the American Ophthalmological Society, an honor society composed of 300 leaders in ophthalmology. He has been listed every year, since 1986, in The Best Doctors in America.
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